Dorsal root ganglion stimulation

Neuromodulation of distal targets such as dorsal root ganglion may permit greater anatomic specificity of the therapy, whereas subthreshold stimulation with high-frequency or burst energy delivery may eliminate noxious and off-target paresthesiae. Such new technologies should be subject to rigorous evaluation as their mechanisms of action and long-term outcomes remain hitherto undefined 1).

Indications

Case series

Piedade et al., from University Hospital of Düsseldorf, reported a consecutive series of 20 patients treated with DRG stimulation in the upper thoracic and cervical region. All patients suffered from chronic neuropathic pain unresponsive to best medical treatment. Main pain etiologies were traumaspine surgerypostherpetic neuralgia, and peripheral nerve surgery. All patients were trialed with externalized electrodes prior to permanent pulse generator implantation. Routine clinical follow-up was performed during reprogramming sessions.

Out of all 20 patients trialed, 18 were successfully trialed and implanted with a permanent stimulation system. The average pain relief after three months compared to the baseline was of 60.9% (mean VAS 8.5 to VAS 3.2). 77.8% of the patients reported a pain relief of at least 50% after three months. One patient developed a transient paresis of the arm caused by the procedure. She completely recovered within three months.

Cervical and upper thoracic DRG stimulation resulted in good overall response rates to trialing and similar pain relief when compared to DRG stimulation for groin and lower limb pain. A modified surgical approach has to be used when compared with lumbar DRG electrode placement. Surgery itself in this region is more complication prone and challenging 2).


Morgalla et al., prospectively enrolled 12 adult patients with unilateral localized neuropathic pain in the lower limbs or inguinal region and followed them up for six months Laser evoked potentials (LEP) were assessed at baseline, after one month of DRGS, and after six months of DRGS. Clinical assessment included the Numerical Rating Scale (NRS), Brief Pain Inventory (BPI), SF-36, and Beck Depression Inventory (BDI). For each patient, LEP amplitudes and latencies of the N2 and P2 components on the deafferented side were measured and compared to those of the healthy side and correlated with pain intensity, as measured with the NRS.

At the one- and six-month follow-ups, N2-P2 amplitudes were significantly greater and NRS scores were significantly lower compared with baseline (all p’s < 0.01). There was a negative correlation between LEP amplitudes and NRS scores (rs = -0.31, p < 0.10).

DRGS is able to restore LEPs to normal values in patients with localized neuropathic pain, and LEP alterations are correlated with clinical response in terms of pain intensity 3).

Case reports

van Velsen et al. used a single-incision approach to tunnel and implant the leads and pulse generator for DRG stimulation treatment in a patient suffering from intractable foot pain. At long-term follow-up, the patient experienced a decrease in pain intensity and improvement in function, without any complications. A single-incision implantation technique for DRG stimulator implantation may simplify implantation and decrease the risk of complications 4).

References

1)

Shamji MF, De Vos C, Sharan A. The Advancing Role of Neuromodulation for the Management of Chronic Treatment-Refractory Pain. Neurosurgery. 2017 Mar 1;80(3S):S108-S113. doi: 10.1093/neuros/nyw047. PubMed PMID: 28350939.
2)

Piedade GS, Vesper J, Chatzikalfas A, Slotty PJ. Cervical and High-Thoracic Dorsal Root Ganglion Stimulation in Chronic Neuropathic Pain. Neuromodulation. 2019 Jan 8. doi: 10.1111/ner.12916. [Epub ahead of print] PubMed PMID: 30620789.
3)

Morgalla MH, de Barros Filho MF, Chander BS, Soekadar SR, Tatagiba M, Lepski G. Neurophysiological Effects of Dorsal Root Ganglion Stimulation (DRGS) in Pain Processing at the Cortical Level. Neuromodulation. 2018 Dec 18. doi: 10.1111/ner.12900. [Epub ahead of print] PubMed PMID: 30561852.
4)

van Velsen V, van Helmond N, Levine ME, Chapman KB. Single-Incision Approach to Implantation of the Pulse Generator and Leads for Dorsal Root Ganglion Stimulation: A Case Report. A A Case Rep. 2017 Aug 14. doi: 10.1213/XAA.0000000000000625. [Epub ahead of print] PubMed PMID: 28816708.

UpToDate: Intraneural ganglion cyst

An intraneural ganglion cyst (INGC) is a non-neoplastic mucinous cyst within the epineurium of a nerve and commences from an adjoining joint 1) 2)3) 4) 5) 6) 7).

These cysts are filled with a mucinous material which is walled off by a fibrous layer 8) 9) 10)

An intraneural ganglion cyst is an uncommon occurrence of the peripheral nerves.

Types

The most common type is the peroneal intraneural ganglion cyst. Other reported sites of involvement are the radial, ulnar, median, sciatic, tibial, and posterior interosseus nerves. The first case of intraneural ganglion cyst of the tibial nerve was described in 1967.

Etiology

According to the most widely accepted theory (articular/synovial theory), the cysts are formed from a capsular defect of an adjacent joint, so that synovial fluid spreads along the epineurium of a nerve branch 11).

Clinical features

As these cysts expand within the epineurium, they displace and compress the adjacent nerve fascicles leading to pain, paresthesia, tingling and muscle paralysis in the distribution of the involved nerve 12) 13).

Diagnosis

MRI is the method of choice for diagnosing intraneural ganglion cysts. However, ultrasound is also important 14).

Differential diagnosis

The differential considerations for cystic intraneural lesions include cystic nerve sheath tumors, atypical Baker’s cyst, and extraneural ganglion.

Cystic nerve sheath tumors such as schwannomas and extraneural ganglion can be differentiated from cystic intraneural lesions by MRI. A Baker’s cyst classically is more mass-like, with a characteristic location extending from the tibiofemoral joint to within the confines of the medial head of the gastrocnemius and the muscles of the joint capsule 15).

Treatment

Surgery is the only curative treatment with treatment success being dependent on ligature of the nerve endings supplying the articular branch 16).

Case series

Fricke et al. from Kiel, examined between 2011 and 2018 the patients using lower limb MRI. MRI scans were also performed for the follow-up examinations.

The patients had many symptoms. They were able to accurately detect the intraneural ganglion cysts on MRI and provide the treating surgeons with the basis for the operation to be performed.

The success of surgical therapy depends on the resection of the nerve endings supplying the joint as the only way to treat the origin of the disease and prevent recurrence. Based on there case studies, they can support the commonly favored articular/synovial theory. 17).

References

1) , 8)

Patel P, Schucany WG. A rare case of intraneural ganglion cyst involving the tibial nerve. Proc (Bayl Univ Med Cent) 2012;25:132–135.

2) , 9)

Uetani M, Hashmi R, Hayashi K, Nagatani Y, Narabayashi Y, Imamura K. Peripheral nerve intraneural ganglion cyst: MR findings in three cases. J Comput Assist Tomogr. 1998;22:629–632.

3) , 10)

Harbaugh KS, Tiel RL, Kline DG. Ganglion cyst involvement of peripheral nerves. J Neurosurg. 1997;87:403–408.

4)

Spinner RJ, Desy NM, Rock MG, Amrami KK. Peroneal intraneural ganglia. Part I. Techniques for successful diagnosis and treatment. Neurosurg Focus. 2007;22:E16.

5)

Jacobs RR, Maxwell JA, Kepes J. Ganglia of the nerve. Presentation of two unusual cases, a review of the literature, and a discussion of pathogenesis. Clin Orthop Relat Res. 1975:135–144.

6)

Adn M, Hamlat A, Morandi X, Guegan Y. Intraneural ganglion cyst of the tibial nerve. Acta Neurochir (Wien) 2006;148:885–889; discussion 889-890.

7)

Johnston JA, Lyne DE. Intraneural ganglion cyst of the peroneal nerve in a four-year-old girl: a case report. J Pediatr Orthop. 2007;27:944–946.

11) , 14) , 16) , 17)

Fricke T, Schmitt AD, Jansen O. Intraneural ganglion cysts of the lower limb. Rofo. 2018 Nov 19. doi: 10.1055/a-0777-2525. [Epub ahead of print] English, German. PubMed PMID: 30453381.

12)

Tehli O, Celikmez RC, Birgili B, Solmaz I, Celik E. Pure peroneal intraneural ganglion cyst ascending along the sciatic nerve. Turk Neurosurg. 2011;21:254–258.

13)

Liang T, Panu A, Crowther S, Low G, Lambert R. Ultrasound-guided aspiration and injection of an intraneural ganglion cyst of the common peroneal nerve. HSS J. 2013;9:270–274.

15)

Patel P, Schucany WG. A rare case of intraneural ganglion cyst involving the tibial nerve. Proc (Bayl Univ Med Cent). 2012 Apr;25(2):132-5. PubMed PMID: 22481843; PubMed Central PMCID: PMC3310510.
intraneural_ganglion_cyst.txt · Last modified: 2018/11/20 20:09 by administrador

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